Heat the oven to 180°C/160°C fan-assisted/Gas Mark 4. Lightly brush the sheets of pastry with oil. Use to line a 20cm loose bottomed, fluted tart tin. Gently spread over the crème fraîche.
Fan out a layer of potato, scatter over the peppers and torn cooked chicken. Layer again with the potato and red onion. Transfer to the oven and bake for 20 minutes until golden and tender when pierced with a knife.
Remove carefully from the tin and serve in slices with a crisp green salad.
400g smooth potatoes, such as Desiree, thinly sliced
4 large sheets filo pastry
2 tbsp sunflower oil
1 large red onion, thinly sliced into rounds
100ml half fat crème fraîche
1 red pepper, finely chopped
1 green pepper, finely chopped
2 cooked chicken breasts, torn
Crisp green salad, to serve